 Heater fan operation, troubleshooting |
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| malcolm2 |
 Dec 14 2013, 08:34 PM
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#1
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Advanced Member  Group: Members Posts: 2,747 Joined: 31-May 11 From: Nashville Member No.: 13,139 Region Association: South East States 
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The only thing installed on my car that is associated with HEAT would be the exchangers. Nothing else. I need to get the heat working so I started with the Heater fan in the engine bay.
SO FAR: successfully bench tested the fan with 12v. Put a known good headlight relay in the fan relay socket Successfully checked continuity of the wire from the lever to the 14-pin connector (GRN/wht). Connector attatched, and unattached Successfully checked continuity from the relay (87) to the fan (green wire), car was not running. Strange thing I noticed. Checking continuity from the lever to Pin #9 was good. I then checked continuity between the lever and pin 13, 11, 7, 5, 3, 2 & 1. With the 14-pin connector connected they all showed continuity to ground. THIS CAN"T BE RIGHT, can it? The car runs fine, all the lights work. Seems like a ground short, but it is not affecting anything else. My goal here was to (as designed) get 12v to the green wire on the fan, but I can't. I have read several posts that gave me some direction. But I am lost. Thanks, Clark  |
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| Dave_Darling |
Dec 14 2013, 11:50 PM
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914 Idiot Group: Members Posts: 15,075 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California
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Not sure about the "continuity with everything" bit.
But here is how the heater blower circuit works: The switch on the bottom of the "DEFROST" lever gets grounded when you pull the lever up high enough. That grounds one of the control pins (85 or 86, forget which) of the heater blower relay, which sends power from #30 of the relay to #87 of the relay. That power is what runs the fan. Power gets to #30 of the relay through one of the fuses on the relay board. I don't remember how power gets to the other control pin of the relay, but it should be "switched power". --DD |
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Posts in this topic
malcolm2 Heater fan operation Dec 14 2013, 08:34 PM
malcolm2
But here is how the heater blower circuit works:
... Dec 15 2013, 09:45 AM
etcmss I've done this a couple of times and briefly r... Dec 15 2013, 06:15 AM Dave_Darling Correct, the switch on the DEFROST lever grounds p... Dec 15 2013, 01:09 PM Mike Bellis Dave is correct about the relay pin numbering.
Ma... Dec 15 2013, 01:30 PM malcolm2
Dave is correct about the relay pin numbering.
M... Dec 15 2013, 01:41 PM |
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